Chromium Network Errors
Browser — 3 error codes
Reference list of 3 Chromium network errors with meanings, common causes, and related context.
About Chromium Network Errors
Chromium network errors (prefixed with ERR_) are diagnostic codes generated directly by the browser's internal network stack. They occur when a connection attempt fails at the transport or presentation layer—before an HTTP response is ever received. These errors provide specific insight into exactly why a connection failed, such as DNS resolution issues, TCP connection rejections, or TLS handshake failures.
Because these errors happen client-side, they are essential for distinguishing between server outages and local network problems. For instance, ERR_CONNECTION_REFUSED means the target server actively rejected the TCP connection, while ERR_CONNECTION_TIMED_OUT means the browser received no response at all, often due to a firewall or routing issue.
This collection documents 3 Chromium network errors. Each entry breaks down the network phase where the failure occurred, what the browser measured during the connection attempt, and how to troubleshoot the underlying configuration fault.
Showing 3 of 3 error codes
Connection Refused — The target server actively rejected the connection attempt.
Connection Timed Out — The browser gave up waiting for a response from the server.
SSL Protocol Error — The secure connection failed during the TLS handshake.
Frequently Asked Questions
This error occurs when the target server actively rejects the initial TCP connection attempt by instantly returning a TCP Reset (RST) packet. It usually indicates that no service is listening on the requested port, or a firewall rule is explicitly rejecting traffic.
An HTTP 500 error is generated by the server after a connection was successfully established. A Chromium network error occurs before the HTTP request could even be sent, meaning the connection failed at the DNS, TCP, or TLS layer.
If the browser sends an initial TCP SYN packet and receives absolutely no response (neither a SYN-ACK nor an RST), it must wait for a hardcoded timeout threshold to expire before giving up. This is usually caused by silent firewall drop rules or network path issues.